1. Field of the Invention
The present invention concerns an oxide-dispersion-strengthened niobium-based alloy having both good oxidation resistance and good heat resistance.
2. State of the Art
Niobium is one of the high-melting point metals (m.p. 1467.degree. C.) and niobium-based alloys are often used as the material of the parts to be exposed to a temperature as high as 1400.degree. C. or more. The niobium-based alloys having high strength at a high temperature, however, have low oxidation resistance, and cannot be used in an oxidizing atmosphere. Though niobium-based alloys with improved oxidation resistance have been developed, strength of the known alloys at high temperatures is still low. Thus, the conventional niobium-based alloys are not satisfactory as the material for structural parts.
There has been proposed a countermeasure to overcome the above problem, which comprises preparing a part with the above noted niobium-based alloy with high strength at high temperatures and coating the surface thereof with powder having oxidation resistance. If, however, the oxidation resisting coating loses the protecting ability due to some reasons such as crack formation in the coating while the part is used or abrasion in case of a sliding member, the niobium-based metals are seriously damaged.